Tory efforts to prevent the term 'bedroom tax' taking hold took on a new urgency today, after Iain Duncan Smith wrote a letter to the BBC demanding they stop using Labour language.
The phrase is stiffly resented by Conservatives, who say the 'spare room subsidy' currently hits taxpayers by charging them for rooms in social housing which are not being used.
"What should not happen is for the BBC to adopt the language of the Labour party without making it clear that the phrase is innately political and indeed, factually wrong," the welfare secretary wrote to the BBC.
"We do not believe it is the job of the BBC to use misleading terms and promote the views of the Labour party.
"The BBC has a duty to inform the public. We believe that the BBC is failing in this duty and confusing members of the public over whether they might be 'taxed'."
Duncan Smith even went so far as to quote from the dictionary definition of what constitutes a tax - a "compulsory contribution to state revenue taken from workers' pay or business profits - or added to the cost of goods and services".
The welfare secretary is undoubtedly correct that the cut to housing benefits for tenants with excess bedrooms does not constitute a tax, but the slow speed with which the Tories responded to the growing Labour campaign against the measure meant they were unable to control the terms of debate once it became major political news.
It is not unusual for political parties to sacrifice technical accuracy for snappy, easily memorable terms which might resonate with the public.
The Conservatives were guilty of similar manoeuvres when they pulled out of talks on social care with Labour so they could accuse the party of promoting a 'death tax'.